Conical burr coffee grinders are well known. It is possible for a conical burr grinder to require cleaning or maintenance to remove grind blockages. In order to disassemble a conical burr grinder for these purposes, typically the lower burr assembly including the conical shaped lower burr is removed from the grinder. In many instances, the lower burr assembly is secured by a nut. When the nut is removed, the lower burr and the related components in the assembly are removed individually. However, it can be difficult for a user to remove some of the small components associated with the lower burr assembly in the small and partially enclosed area of the grind chamber. Further, the user may be unfamiliar with a particular order of re-assembly, each of the components. In some instances, user will employ a vacuum cleaner to remove debris from the grind chamber. If the user has not removed all of the components, these may inadvertently be drawn into the vacuum cleaner. In some instances, the nut that secures the lower burr assembly is reverse threaded or may need a specific tool that can fit within the restricted space of the grind chamber.
A tamping augur comprises a rotating augur fan that fits within or otherwise cooperates with the filter basket of a portafilter. The augur fan of the tamping augur rotates within the filter basket to both compress the ground coffee in the filter basket and create a uniform upper surface. However, it is practically inevitable that there will be a clearance between the outer periphery of the augur fan and the inner wall of the filter basket. It is undesirable to have ground coffee attached to the inner wall of the filter basket above the level of the compacted grinds.
It is known to combine an espresso making machine with an integral coffee grinder. However, the tamping of the grinds into the portafilter requires skill. Users that do not possess this skill would benefit from a motorised tamping augur integrated with the coffee grinder. It would he additionally convenient to allow the grinder and augur to be operated by the action of the portafilter without resort to other user controls such as push buttons.
Boilers in an espresso coffee maker such as a steam generating boiler and a boiler for heating water for coffee accumulate scale during use. The extent of the scale depends on the hardness of the water being used. The accumulating scale degrades the performance and longevity of the boilers.
It is known to incorporate a conical burr grinder in an espresso machine. A conical burr grinder has an upper burr and a generally conically lower burr that forms a portion of a lower burr assembly. When the coffee grinder is dirty, obstructed or jammed, it may be necessary to remove the lower burr assembly from the grinder. This is often complicated, inconvenient or requiring special tools.
The performance of a motorised tamping augur can also be potentially improved by incorporating a height adjustment mechanism for the augur fan. In this way, inconsistencies in manufacturing and user preferences regarding the compaction height of a dose and portafilter may be user adjusted, as required.
Some tamping augurs also provide for less than uniform distribution and compaction of the grounds below augur fan, within the portafilter. Irregularities in the distribution of coffee grinds result in a less than optimal brew because water flowing through the portafilter will tend to bypass more compacted areas in favour of less compacted areas.
In an automated or semi-automated machine, methods and apparatus are also required for determining when a pre-established fill height or level of compaction has been reached with respect to the grinds in a portafilter.
Tamping augurs, augur heads such as fan type heads are disclosed in the Applicant's PCT application PCT/AU2011/001263.